package com.learn.designpattern.singleton.type2;

public class SingletonTest02 {

    public static void main(String[] args) {

        Singleton instance=Singleton.getInstance();
        Singleton instance2=Singleton.getInstance();

        System.out.println(instance==instance2);
        System.out.println("instance.hashCode=" + instance.hashCode());
        System.out.println("instance2.hashCode=" + instance2.hashCode());
    }
}

//饿汉式(静态变量)
class Singleton{

    //1. 构造器私有化, 外部能new
    private Singleton() {

    }

    //2.本类内部创建对象实例
    private  static Singleton instance;

    static {// 在静态代码块中，创建单例对象
        instance=new Singleton();
    }

    //3. 提供一个公有的静态方法，返回实例对象
    public static Singleton getInstance(){
        return instance;
    }

}
